Messages in this thread Patch in this message | | | From | Yazen Ghannam <> | Subject | [PATCH 3/3] x86/mce/AMD: Use saved threshold block info in interrupt handler | Date | Wed, 24 May 2017 15:41:47 -0500 |
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From: Yazen Ghannam <yazen.ghannam@amd.com>
In the amd_threshold_interrupt() handler, we loop through every possible block in each bank and rediscover the block's address and if it's valid, e.g. valid, counter present and not locked. However, we already have the address saved in the threshold blocks list for each CPU and bank. The list only contains blocks that have passed all the valid checks.
Besides the redundancy, there's also an smp_call_function* in get_block_address() and this causes a warning when servicing the interrupt.
WARNING: CPU: 0 PID: 0 at kernel/smp.c:281 smp_call_function_single+0xdd/0xf0 ... Call Trace: <IRQ> rdmsr_safe_on_cpu+0x5d/0x90 get_block_address.isra.2+0x97/0x100 amd_threshold_interrupt+0xae/0x220 smp_threshold_interrupt+0x1b/0x40 threshold_interrupt+0x89/0x90
Iterate over the threshold blocks list and use the saved address. Also, drop the redundant valid checks.
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> --- arch/x86/kernel/cpu/mcheck/mce_amd.c | 27 ++++++++++----------------- 1 file changed, 10 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c index 2074b870..14e4dab 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c @@ -873,30 +873,23 @@ static void log_error_thresholding(unsigned int bank, u64 misc) */ static void amd_threshold_interrupt(void) { - u32 low = 0, high = 0, address = 0; - unsigned int bank, block, cpu = smp_processor_id(); + u32 low = 0, high = 0; + unsigned int bank, cpu = smp_processor_id(); struct thresh_restart tr; + struct threshold_block *block = NULL, *tmp = NULL; + struct list_head *head = NULL; for (bank = 0; bank < mca_cfg.banks; ++bank) { if (!(per_cpu(bank_map, cpu) & (1 << bank))) continue; - for (block = 0; block < NR_BLOCKS; ++block) { - address = get_block_address(cpu, address, low, high, bank, block); - if (!address) - break; - if (rdmsr_safe(address, &low, &high)) - break; + if (!per_cpu(threshold_banks, cpu)[bank]->blocks) + continue; - if (!(high & MASK_VALID_HI)) { - if (block) - continue; - else - break; - } + head = &per_cpu(threshold_banks, cpu)[bank]->blocks_head; - if (!(high & MASK_CNTP_HI) || - (high & MASK_LOCKED_HI)) + list_for_each_entry_safe(block, tmp, head, miscj) { + if (rdmsr_safe(block->address, &low, &high)) continue; if (!(high & MASK_OVERFLOW_HI)) @@ -907,7 +900,7 @@ static void amd_threshold_interrupt(void) /* Reset threshold block after logging error. */ memset(&tr, 0, sizeof(tr)); - tr.b = &per_cpu(threshold_banks, cpu)[bank]->blocks[block]; + tr.b = block; threshold_restart_bank(&tr); } } -- 2.7.4
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